Many different industrial operations require unloading containers from shelved racking. Typically, containers with goods are loaded on wheeled racks for transport to a location in the plant where further processing of the goods is to take place. Each rack shelf may support a single container or multiple containers. For example, in broiler hatchery operations, eggs are typically stored in multiple containers on each shelf, called multi-piece flats, for storage and handling. Operationally, a container must be unloaded from the rack and moved or transported to an operational piece of equipment, such as a conveyor for further downstream processing in the plant facility.
In these and other operations, the distance between shelves is typically small and leaving minimal clearance between the goods in each container and the shelf above. The spacing and configuration of the shelves on these racks is not standardized and can vary rack-to-rack, even within the operations at a single facility. This creates a challenge for automation because the rack unloading apparatus must be able to effectively remove containers from variously configured racks.
Known automated rack unloading systems and apparatus remove containers from the racks by hooking the edge of the container and pulling it off the shelf. This approach is only practical where a single container is stored on each shelf. In the case where multiple containers are stored on each shelf, each container on the shelf would have to be individually hooked and removed which increases the time required to unload each rack. It would be preferable to simultaneously remove multiple containers from each shelf in a single operation.
Other known automated rack unloading systems for multi-piece containers or flats insert a “spoon” under the container(s) to thereby load the container(s) on the spoon. The spoon and the container(s) are withdrawn thereby unloading the rack shelf. This requires that the leading edge of the spoon be referenced and guided to a pre-programmed position on the shelf which is the contact point between the bottom of the container(s) and shelf surface so as to be insertable thereunder. Programming this position is unreliable given the variation in rack design, shelf pitch and flat designs.
Accordingly, there is a need for an automated rack unloading apparatus that is able to meet these objects and reliably maintain the high unloading processing rates demanded of automated equipment in modern operations. Furthermore, it would be desirable to provide an associated method.